Classic/Antique Car Repair: mastercylinder, drum brakes, disc brakes

Question
Dick,  is it possible to use a blow gun and blow the gunk out of the plugged reservoir.  I put the after market discs on and I had to find a mc for it.  It didn't take a lot to find on just the right push rod size and then we went from there.
kevin---------------------

Followup To

Question -
Dick..
You hit the nail on the head in the last response pertaining to bleeding the mc.  I am not getting anything out of the rear reservoir and have cleaned the insides of the mc, talk about gross!  Anyway is there anyway that I can clean out the mc before I attempt to add fluid and begin the bleeding process again.  I do believe that the ports in the rear reservoir might be plugged, no sense in adding more fluid if it will not go through. kevin

Answer -
It is not too hard to take the master cylinder apart to clean it out, but I don't know of any other way to get it clean than to do that.

I think if you know what master cylinder it is (you said you had aftermarket front disc brakes, and disc brakes require a different master cylinder than drum brakes, so the master cylinder would have been changed from original if the car was converted from drum to disc), I think you'd be much wiser to just buy a new master cylinder and replace it.  They don't cost much more than the kit to rebuild it, and if you don't have experience taking them apart and rebuilding them, and the hone required, you'll come out safer and cheaper by putting a new one on the car. If you don't know what the correct master cylinder is, you'll have to take in the old one to a store where they have the patience to look at it and try to match it up.  If you know who did the conversion to front discs, that person should be able to tell you what master cylinder you need.

Dick

Answer
No, you have to take it all apart to clean it, and you will almost certainly need to buy a kit and a hone and go through the rebuilding process, even though it worked before - as it must have crud in the various valves and passages inside the unit - you can't get at it to do a thorough cleaning job without a complete disassembly - all you have access to is the reservoir, and that isn't where the problem is.

Before you go to all that trouble, just buy another identical unit and install it.  You'll be done with the problem and you'll be safe!

Sorry,

Dick